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All,

Well now there's a thing.

Rx is now fine - original fault ????

Tx, is FUBAR!

I know why but not why.

In Rx there is a nice signal on the Clk0 & Clk1 lines at the Rx frequency and they are 90 Degrees apart.

On Tx then the frequency on those lines doubles! i.e. if 40M set then 15-ish MHz is seen. They are correctly phased on the gates of the FETs (removed but looks like I didn't need to).

If I run a sweep the Clk0 & Clk1 sweep across the frequency band set but Clk2 is ~2F

That's not right!

A reload of the firmware & factory reset results in the same result!

That explains the sweeps - all well out of range as Clk2 is also 2F not F.

Ideas - Hans?

Regards & thanks for the help

Nick
M0HGU
--
What your soldier wants - really, really wants - is no-one shooting
back at him. (alt.fan.pratchett)
Wed 10984 Sep 16:40:02 BST 1993
16:40:02 up 3 days, 23:37, 8 users, load average: 0.74, 0.38, 0.39



--
73 Nick M0HGU

On 28/09/2023 05:04, Hans Summers wrote:

Hello Nick

On Tx then the frequency on those lines doubles! i.e. if 40M set then
15-ish MHz is seen. They are correctly phased on the gates of the FETs
(removed but looks like I didn't need to).

Where and how are you measuring this?

If I run a sweep the Clk0 & Clk1 sweep across the frequency band set but
Clk2 is ~2F

That's not right!

Not right! Hardly even possible :-/ I'd suggest a factory reset but
you've already done that. So how are you measuring Clk2 and ARE YOU SURE it
is 2F?

Morning Hans,

Indeed I don't know how it is possible but - evidence attached.

Rx_clocks is Clk0 & Clk1 at rest Rx-ing in the 40M band - correct frequency and phasing.

Tx_clocks are the same signals just using the terminal transmit test function. I made no changes to the scope settings!

Again correct phasing but the frequency has gone 'wrong'

The other two are self titled and are are self explanatory - again no change to scope settings were made.

I've just done another factory reset and <TA DA!>

No change :-(

I've included the config screens just in case you can see something I can't.

The waveform shape is a function of the sub-optimal wiring to get to the signals (i.e. long)

Many thanks for any insight (or help) you can provide

Regards

Nick
M0HGU

p.s. if groups.io mangle the images I can send them direct or put them on a web page somewhere.

--
"Out of Print" is bookseller speak for "We can't be
hedgehogged". (alt.fan.pratchett)
Thu 10985 Sep 09:15:01 BST 1993
09:15:01 up 4 days, 16:12, 8 users, load average: 0.40, 0.50, 0.52



--
73 Nick M0HGU

On 28/09/2023 09:37, Nick Norman wrote:

On 28/09/2023 05:04, Hans Summers wrote:

Where and how are you measuring this?

Hans,

Sorry I meant to answer this bit - at Clk0 & Clk1 on IC4 and Clk2 at R19

Regards

Nick
M0HGU

--
A lot of people and the smell of sausages meant a performance of the
street theatre that was life in Ankh-Morpork. (Feet of Clay)
Thu 10985 Sep 09:40:01 BST 1993
09:40:01 up 4 days, 16:37, 8 users, load average: 0.53, 0.65, 0.63



--
73 Nick M0HGU

On Wed, Sep 27, 2023 at 04:55 PM, Nick Norman wrote:

That explains the sweeps - all well out of range as Clk2 is also 2F not F.

Nich,

Clock 2 is not relevant on TX.
I note the scope, Hantek. USB?
What is the output frequency at the antenna? Best check with a counter or RX.

73 Alan G4ZFQ

On 28/09/2023 10:47, Alan G4ZFQ wrote:

On Wed, Sep 27, 2023 at 04:55 PM, Nick Norman wrote:

That explains the sweeps - all well out of range as Clk2 is also 2F not F.

Nich,
Clock 2 is not relevant on TX.

Indeed

I note the scope, Hantek. USB?

No, 200 MHz 1 Gs/s

What is the output frequency at the antenna? Best check with a counter or RX.

As per the Tx_clocks.png - but I pulled the BS170s so can't actually measure after the LPFs at present. I checked the frequency of the clocks with a counter - it agrees with the scope.

I can confirm that IC5 is fully functional.

Regards

Nick

--
Guilt was the grease in which the wheels of the authority turned.
(Small Gods)
Thu 10985 Sep 10:50:01 BST 1993
10:50:01 up 4 days, 17:47, 8 users, load average: 0.26, 0.53, 0.62



--
73 Nick M0HGU

On 28/09/2023 09:55, Nick Norman wrote:

? I checked the frequency of the clocks with a counter - it agrees with the scope.

Nick, OK, when I get unexpected measurements then, like Hans, I first question my measuring techniques.
If the frequency really is double then it looks like the 5351 has a weird fault.

73 Alan G4ZFQ